Perl Programm needed

I need a translation of a Visual Basic program to [login to view URL] program sets the device attached to the serial port to a specific mode for recording noise (in dB(A)) and was designed for VB on Windows. I need this for an open source project on Rasberry PI. The original program is attached. I just need the converted functions to set the mode to 1 (1 Microphone, 1000ms) or 2 (2 Microphones input, 1000ms). There is no need for GUI or other functions. Direct access via GRE or L2TP to Rasberry is possible, also L2TP for Windows with attached hardware Device is possible. So remote work can be done. There is some more programming where I could need help, so this is just the first snipplet. The original Program is: VERSION 5.00 Begin [login to view URL] Form1 Appearance = 0 '2D BackColor = &H80000016& Caption = "DBA-Logger Modus" ClientHeight = 4770 ClientLeft = 1590 ClientTop = 1500 ClientWidth = 6015 BeginProperty Font Name = "MS Sans Serif" Size = 8.25 Charset = 0 Weight = 700 Underline = 0 'False Italic = 0 'False Strikethrough = 0 'False EndProperty ForeColor = &H80000008& LinkTopic = "Form1" PaletteMode = 1 'ZReihenfolge Picture = "[login to view URL]":0000 ScaleHeight = 4770 ScaleWidth = 6015 Begin [login to view URL] Command3 Caption = "Testen" Height = 735 Left = 360 TabIndex = 7 Top = 3480 Width = 1815 End Begin [login to view URL] Combo1 BeginProperty Font Name = "MS Sans Serif" Size = 12 Charset = 0 Weight = 700 Underline = 0 'False Italic = 0 'False Strikethrough = 0 'False EndProperty Height = 420 Left = 2520 TabIndex = 5 Text = "Combo1" Top = 2400 Width = 3015 End Begin [login to view URL] Command2 Caption = "Modus ändern" Height = 735 Left = 360 TabIndex = 4 Top = 2280 Width = 1815 End Begin [login to view URL] Text3 BeginProperty Font Name = "MS Sans Serif" Size = 12 Charset = 0 Weight = 700 Underline = 0 'False Italic = 0 'False Strikethrough = 0 'False EndProperty Height = 495 Left = 2520 TabIndex = 3 Top = 1320 Width = 735 End Begin [login to view URL] Command1 Caption = "Modus lesen" Height = 735 Left = 360 TabIndex = 2 Top = 1200 Width = 1815 End Begin [login to view URL] Text1 BeginProperty Font Name = "MS Sans Serif" Size = 12 Charset = 0 Weight = 400 Underline = 0 'False Italic = 0 'False Strikethrough = 0 'False EndProperty Height = 360 Left = 2640 TabIndex = 1 Text = "1" Top = 240 Width = 255 End Begin [login to view URL] Text2 Appearance = 0 '2D BeginProperty Font Name = "MS Sans Serif" Size = 12 Charset = 0 Weight = 700 Underline = 0 'False Italic = 0 'False Strikethrough = 0 'False EndProperty Height = 495 Left = 2520 TabIndex = 0 Text = "0" Top = 3600 Width = 2175 End Begin [login to view URL] Label1 Caption = "Bitte COM wählen" Height = 255 Left = 480 TabIndex = 6 Top = 360 Width = 1575 End End Attribute VB_Name = "Form1" Attribute VB_GlobalNameSpace = False Attribute VB_Creatable = False Attribute VB_PredeclaredId = True Attribute VB_Exposed = False Dim n Dim Integral Dim Modus Private Sub Command1_Click() OpenString = "COM" + [login to view URL] + ":9600,N,8,1" i = OPENCOM(OpenString) If i = 0 Then MsgBox ("Schnittstelle nicht verfügbar") Else DTR 1 RTS 1 TIMEINIT SENDBYTE 27 CLEARBUFFER d = READBYTE() If d = 27 Then SENDBYTE 11 d = READBYTE [login to view URL] = Str(d) If d > 0 Then Modus = d Else CLOSECOM OpenString = "COM" + [login to view URL] + ":19200,N,8,1" i = OPENCOM(OpenString) DTR 1 RTS 1 TIMEINIT CLEARBUFFER SENDBYTE 11 d = READBYTE If d > 0 Then If d = 5 Then Modus = 5 [login to view URL] = Str(d) End If End If End If End If End Sub Private Sub Command2_Click() Neumodus = [login to view URL] + 1 If Neumodus = 0 Then Neumodus = 1 Text3 = Neumodus If Modus < 5 Then SENDBYTE 27 CLEARBUFFER d = READBYTE() DELAY 5 If d = 27 Then SENDBYTE 10 d = READBYTE() DELAY 5 SENDBYTE Neumodus End If End If If Modus = 5 Then CLEARBUFFER SENDBYTE 10 d = READBYTE() DELAY 5 SENDBYTE Neumodus End If If Modus = 5 Then OpenString = "COM" + [login to view URL] + ":19200,N,8,1" If Modus < 5 Then OpenString = "COM" + [login to view URL] + ":9600,N,8,1" End Sub Private Sub Command4_Click() OpenString = "COM" + [login to view URL] + ":9600,N,8,1" i = OPENCOM(OpenString) If i = 0 Then MsgBox ("Schnittstelle nicht verfügbar") DTR 1 RTS 1 End Sub Private Sub Command3_Click() If Modus = 1 Then CLEARBUFFER DELAY 1000 d = READBYTE L = (d - 50) / 2 If L < 0 Then L = 0 [login to view URL] = " " + Str$(L) + " dB(A)" End If If Modus = 2 Then CLEARBUFFER DELAY 1000 For n = 1 To 4 d = READBYTE If d = 1 Then d = READBYTE L = (d - 50) / 2 If L < 0 Then L = 0 [login to view URL] = " " + Str$(L) + " dB(A)" End If Next n End If If Modus = 3 Then CLEARBUFFER DELAY 1000 d = READBYTE L = (d - 50) / 2 If L < 0 Then L = 0 [login to view URL] = " " + Str$(L) + " dB(A)" End If If Modus = 4 Then CLEARBUFFER For n = 1 To 4 d = READBYTE DELAY 1000 If d = 1 Then d = READBYTE L = (d - 50) / 2 If L < 0 Then L = 0 [login to view URL] = " " + Str$(L) + " dB(A)" End If Next n End If If Modus = 5 Then CLEARBUFFER SENDBYTE 48 d = READBYTE L = (d - 50) / 2 If L < 0 Then L = 0 [login to view URL] = " " + Str$(L) + " dB(A)" End If End Sub Private Sub Form_Load() [login to view URL] "M 1, 1 Ch 1000 ms " [login to view URL] "M 2, 2 Ch 1000 ms " [login to view URL] "M 3, 1 Ch 600 ms " [login to view URL] "M 4, 2 Ch 600 ms " [login to view URL] "M 5, SIOS-kompatibel" [login to view URL] = 0 Modus = 1 End Sub Private Sub Form_Unload(Cancel As Integer) CLOSECOM End Sub